Electrical connector for flexible flat cable

ABSTRACT

An electrical connector with upper contacts, for a flexible flat cable. The connector is an electrical connector for gripping a flexible flat cable by upper contacts, and the connector includes two kinds of contact members for gripping the flexible flat cable, a housing for receiving the contact members, and an opening/closing type actuator. The contacts of the two kinds of the contact members are spaced from each other in an insertion direction, and the contact members are alternately arranged in the housing so as to form staggered rows of the contacts. With a first kind of contact members, FPC can be inserted without insertion force, and with a second kind of contact members, the FPC can be inserted with low insertion force. The connector is characterized in that is has a zero insertion force (Z.I.F.) and low insertion force (L.I.F.) mechanism structure for insertion of the FPC, where the structure is constructed from the first contact members and second contact members.

TECHNICAL AREA

The present invention concerns an electrical connector that connectsflat flexible cables (FPC (Flexible Printed Cable) and FFC (FlexibleFlat Cable) and the like are this type of cable, but herebelow in thepresent specification, they shall be called FPC).

BACKGROUND ART

Japanese Unexamined Patent Publication No. 2002-190360 discloses aconnector wherein, in a FPC connector having a plurality of contactswhich grip terminal portions of printed circuit boards, opposed grippingaction contacts and fixed pieces are formed separately. In saidconnector, the gripping action contacts comprise two types of grippingaction contacts with differing lengths, and gripping action contactswith differing lengths are placed so that they are adjacent to eachother, so that the contact portions of the ends of the gripping actioncontacts are placed in a staggered manner. Additionally, fixed piecesaffixed to the body at locations corresponding to each of the contactpoints are formed. The space between each of the opposing contact pointsis smaller than the thickness of a FPC, and when a FPC is inserted,there is a low insertion force (LIF) because of contact with each of thecontact points. That is, after insertion, the FPC first comes intocontact with a first contact point, and further, when inserted moredeeply, it comes into contact with a second contact point, and isgripped by the elastic force of the gripping action contact at eachcontact point. In the next action, gripping action contacts withdifferent lengths are elastically deformed by an actuator, in order togrip the FPC even more strongly.

However, according to this structure, when the inserted FPC is gripped,a pressing force due to the actuator is further added to the elasticforce of the gripping action contacts, so that it becomes easy forwarping to arise in the aforementioned FPC, and four parts, being thecontact portions and fixed piece portions of the first and secondcontact points must be manufactured, so that an increase inmanufacturing cost is incurred.

Additionally, Japanese Unexamined Patent Publication No. 2002-134194discloses a connector wherein, in a FPC (flat cable) connector, thereare two types of contacts being a first type and a second type separatedand placed towards the anterior and posterior of the insertiondirection, pressing portions provided for the first contacts, anddriving portions (actuator) provided for the second contacts. Thepressing portions are supported so that they can be brought closer to orseparated from the first contacts provided to the anterior of theinsertion direction, and they come into contact with the aforementionedFPC by being brought close to the aforementioned first contacts, andpushing the first contact points onto the first contacts. The drivingportions contact the aforementioned FPC by being brought close to thesecond contacts provided to the posterior of the insertion direction,and by doing so, the second contact points are pressed onto theaforementioned second contacts, and simultaneously, the aforementionedpressing portions are driven and brought close to the first contacts.

A structure is disclosed wherein the contact points of the first andsecond contacts of the aforementioned connector are provided on the baseside whereon the FPC is gripped, and so-called gripping at lowercontacts is realized. In order to solve the problems of the conventionalart that when a flat cable is inserted, the contacts are damaged, orthat imperfect connection states can arise, and in order to solve theproblem of the conventional art that since the operation of inserting aflat cable against a low resistance force is required, operability isinferior, in said connector, insertion can be done against the secondcontacts in the posterior of the insertion direction with no insertionforce (Zero Insertion Force: ZIF), and insertion can be done against thefirst contacts in the anterior of the insertion direction with a lowinsertion force (Low Insertion Force: LIF).

However, at the present time, there is a demand for electricalconnectors with various other shapes which realize industrialapplicability, for example structures that are adapted for boards whichare compatible with electrical connectors.

DISCLOSURE OF THE INVENTION

The present inventors, as a result of keen investigation, suggest asfollows a new structure that grips a FPC by upper contact points, inresponse to the aforementioned demands.

According to an embodiment of the present invention, the electricalconnector of the present invention is an electrical connector whichgrips a FPC, and said connector is equipped with two types of contactswhich grip the aforementioned FPC, a body which houses said contacts,and an opening and closing actuator.

The contact points of the aforementioned two types of contacts areseparated by a space in the insertion direction, and they comprise a rowof contact points in a staggered form by alternately aligning each saidtype of contact within the aforementioned body.

In the first type of contact, one end of a first contact beam having afirst contact point in contact with a first surface of a FPC, and oneend of a fixed base beam supporting a second surface of theaforementioned FPC are joined, and each of the other ends of the firstcontact beam and fixed base beam which oppose each other are free ends.

Said first contact beam has an actuator-driven portion in the vicinityof the aforementioned free end, and when the actuator is opened, saidactuator-driven portion elastically deforms the aforementioned free endof the aforementioned first contact beam, and opens the aforementionedfree end in the opposite direction from the aforementioned base beam,and when the actuator is closed, by releasing the elastic deformation ofthe aforementioned free end of the aforementioned first contact beam,the aforementioned first contact point comes into contact with theaforementioned first surface of the FPC.

The second type of contact is integrally formed through an attachingportion by a second contact beam and a fixed base beam which oppose eachother.

Said second contact beam has one free end having an actuator-drivenportion in its vicinity, and another free end having a second contactpoint in contact with the first surface of the aforementioned FPC, andhas a structure wherein, due to the fact that when the actuator isclosed, the driving portion of the actuator presses upon theaforementioned one free end of the second contact beam, and elasticallydeforms the aforementioned second contact beam, so that the secondcontact point of the aforementioned other free end presses on the firstsurface of the FPC.

In the electrical connector according to the present invention, forexample, when the actuator is opened (activated), the first contactshave a structure whereby the first contact beam is pressed andelastically deformed so that the first contact point to the posterior ofthe insertion direction is released and an FPC can be inserted with noinsertion force, and the second contacts have a structure whereby thesecond contact beam has a second contact point to the anterior of theinsertion direction when a FPC is inserted, so a low insertion force isneeded for complete insertion. That is, due to the first contacts andthe second contacts, a structure with zero insertion force (ZIF) and lowinsertion force (LIF) during FPC insertion is realized.

Additionally, when the actuator is closed, in the first contacts, theaforementioned one end of the pressed and elastically deformed firstcontact beam is released from being restrained, and when it tries toreturn to its original position by its own elastic force, the firstcontact point on said first contact beam comes into contact with thefirst surface of the FPC, and a pressing force acts and grips the FPCalong with the support portion of the base side, that is, the FPC isgripped by the upper contact point and the lower support portion. Thesecond contacts have a structure wherein, in a state where a FPC iscompletely inserted with a low insertion force, the second contact beamelastically deforms due to the driving portion of the actuator, andpresses upon the first surface of the FPC with the second contact pointon said second contact beam.

According to another embodiment of the present invention, theaforementioned second contact beam of the second contact has a highrigidity from the one end that is the actuator-driven portion to theaforementioned attaching portion, and has a low rigidity from saidattaching portion to the other end.

For example, by increasing the rigidity by making the length from theone end that is the actuator-driven portion of the aforementioned secondcontact beam to the aforementioned attaching portion long, selecting amaterial with high rigidity, or making the thickness of said secondcontact beam thicker, a high pressing force can be applied on theactuator-driven portion. Further, by lowering the rigidity by selectinga material with low rigidity for the portion from the aforementionedattaching portion to the other end, or making the thickness of thesecond contact beam thinner, the second contact point that is theaforementioned other end can respond flexibly to the resistance forcefrom the FPC.

According to another embodiment of the present invention, theaforementioned second contact beam of the electrical connector of thepresent invention is slanted in the direction of the aforementionedfixed base.

In addition to the material and elastic force of the aforementionedsecond contact beam, by giving it a free slanting angle, the contactpressure between the aforementioned second contact point and the FPC canbe freely adjusted.

According to another embodiment of the present invention, the lengths ofeach of the contact beams of the aforementioned two types of contactsare determined so that there is a constant space between the contactpoints in the FPC insertion direction.

For the location of the contact point on the aforementioned firstcontact beam of the aforementioned first type of contact having zeroinsertion force and the location of the contact point on theaforementioned second contact beam of the second type of contact havinglow insertion force, by providing a constant space in the contact beamdirection, the lengths and locations of the contact points of thecontact beams of each of the contacts can be determined freely, forexample, providing a contact point for a zero insertion force contact onthe FPC insertion side, and a contact point for a low insertion forcecontact on the opposite side.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 shows an embodiment of the electrical connector for FPC of thepresent invention, FIG. 1( a) being a top view, and FIG. 1( b) being afront view from the insertion surface side.

FIG. 2 is a side view of an aforementioned metallic contact 2 providedwithin the body 4, with the actuator 5 open.

FIG. 3 is a side view of an aforementioned metallic contact 2 providedwithin the body 4 with the actuator 5 closed.

FIG. 4 is a side view of an aforementioned metallic contact 3 providedwithin the body 4 with the actuator 5 open.

FIG. 5 is a side view of an aforementioned metallic contact 3 providedwithin the body 4 with the actuator 5 closed.

EXPLANATION OF REFERENCE NUMERALS

-   1 . . . electrical connector for FPC-   2 . . . first contact-   3 . . . second contact-   4 . . . body-   5 . . . actuator-   6 . . . first contact beam-   7 . . . first fixed base beam-   8 . . . engaging portion-   9 . . . protruding portion of actuator driving portion-   10 . . . first contact point-   11 . . . second contact beam-   12 . . . actuator driving portion-   13 . . . second fixed base beam-   14 . . . actuator driving portion-   15 . . . base side support portion-   16 . . . end portion having second contact point-   17 . . . base side support portion

BEST MODE FOR EMBODYING THE INVENTION

FIG. 1 shows an embodiment of the electrical connector for FPC accordingto the present invention. FIG. 1( a) is a top view, and FIG. 1( b) is afront view from the insertion side. Said connector is equipped with twotypes of metallic contacts 2 and 3, a body 4, and an actuator 5 thatrotates around a protruding portion (not shown) formed in the vicinityof both ends in the longitudinal direction on the insertion directionside of said body. The FPC inserted into said connector, represented byalternating long and short dashed lines in FIGS. 2 through 5, hascontact points corresponding to the contact points 10 and 16 of theelectrical connector 1, and the contact portions of said FPC and theelectrical connector are placed in a staggered manner with a space inbetween in the cable direction.

FIG. 2 is a side view of an aforementioned metallic contact 2 providedwithin the body 4 with the actuator 5 open. Said metallic contact 2 isinserted into the opposite side surface from the FPC insertion surface,and is locked in place in one end of the bottom surface of the bodywhich engages the engaging portion 8 with the driving portion 12 of theactuator and the base portion 7. Further, in said metallic contact 2,each of one of the ends of the opposing base beam 7 and the firstcontact beam 6 are joined, and each of the other ends of the base beam 7and the first contact beam 6 are free ends. An engaging portion 8 isformed on the free end portion of said first contact beam, which engagesa driving portion 12 of an actuator, and when the actuator is opened,the aforementioned driving portion 12 of an actuator opens theaforementioned free ends being the FPC insertion port, by pushing theengaging portion 8 of the aforementioned first contact beam 6 upwards ina direction perpendicular to the first surface of the FPC, andelastically deforming said first contact beam 6. At that time, the spacebetween the aforementioned open portions is greater than the thicknessof the FPC, so that the FPC never comes into contact with the contactpoint 10 protruding from the first contact beam. Therefore, the metalliccontact 2 realizes zero insertion force (ZIF).

FIG. 3 is a side view of an aforementioned metallic contact 2 providedwithin the body 4 with the actuator 5 closed. In the state where theactuator is completely closed, the upper surface of the body is flush.Additionally, since the elastic deformation due to the aforementionedpressing force of the aforementioned driving portion 12 of the actuatoris released, the first contact beam 6 returns to its original stateunder its own elastic force, and since the free end 10 of the firstcontact beam 6 opposing the base beam which was open, closes, this comesinto contact with the FPC and grips it.

FIG. 4 is a side view of an aforementioned metallic contact 3 providedwithin the body 4 with the actuator 5 open. Said metallic contact 3 isinserted from the FPC insertion surface, and is locked in place in theinsertion surface side end portion of the bottom surface of the bodywhich engages the base portion 13. Further, said metallic contact 3 isintegrally formed through a joining portion between the opposing secondcontact beam 11 and the base beam 13. In said second contact beam, thevicinity of one free end is in contact with the surface in thelongitudinal direction of the driving portion 14 of the rectangularactuator, and extends to the other end from said contact portion in theopposing base beam direction at a slanted angle. When an FPC isinserted, the second surface of the FPC is guided along the top of thebase beam 13 while the first surface of the FPC is in contact with theaforementioned second contact beam. The FPC is completely inserted as isunder low insertion force (LIF).

FIG. 5 is a side view of an aforementioned metallic contact 3 providedwithin the body 4 when the actuator 5 is closed. The moving portion 14of the aforementioned actuator rotates along with the closing motion ofthe aforementioned actuator, and presses upward on the aforementionedsecond contact beam free end in a direction perpendicular to the firstsurface of the FPC, elastically deforming said second contact beam, andas a result, the second contact point being the other end of said secondcontact beam 11 further presses on the first surface of the FPC andgrips the FPC.

The structures of two types of contacts have been explained above, butthe connector according to the present invention is not restricted tothe embodiments described in the specification.

In each attached drawing, the adjacent contacts are omitted and notshown. The alternating long and short dashed lines shown in FIGS. 2–5show the insertion location of an FPC.

EFFECTS OF THE INVENTION

With an electrical connector having an upper contact point with astructure wherein, when an FPC is inserted, zero insertion force and lowinsertion force are simultaneously created, and two types of contactsare placed alternately in a staggered manner, a warping preventingeffect and an operability improving effect can be expected during FPCinsertion and when the FPC is gripped. Said electrical connector can besaid to be an invention that has similar functions to electricalconnectors with a lower contact point structure, that is responsive toindustrial demands and usability.

1. An electrical connector characterized by being an electricalconnector for gripping a flat flexible cable, said connector having twotypes of contacts for gripping the aforementioned flat flexible cable, abody for housing said contacts, and an actuator which opens and closes,having a structure wherein there is a space in the insertion directionbetween each of the contact points of the aforementioned two types ofcontacts, and a row of contact points in a staggered form is constitutedby aligning said each contact alternately within the aforementionedbody, in the contacts of the first type, one end of a first contact beamhas a first contact point that comes into contact with a first surfaceof a flat flexible cable and one end of a fixed base beam supports asecond surface of the aforementioned flat flexible cable beingconnected, and each of the opposing other ends of the first contact beamand the fixed base beam are free ends, said first contact beam has anactuator-driven portion in the vicinity of the aforementioned free end,said actuator-driven portion having a structure such that, when theactuator is open, the aforementioned free end of the aforementionedfirst contact beam is elastically deformed to open the aforementionedfree end in the opposite direction from the aforementioned base beam,and when the actuator is closed, by releasing the elastic deformation ofthe aforementioned free end of the aforementioned first contact beam,the aforementioned first contact point is put into contact with thefirst surface of the aforementioned flat flexible cable, the second typeof contact is integrally formed by an opposing second contact beam andfixed base beam through a joining portion, said second contact beam hasone free end having an actuator-driven portion in the vicinity of saidsecond contact beam, and another free end having a second contact pointwhich comes into contact with the first surface of the aforementionedflat flexible cable, and when the actuator is closed, the drivingportion of the actuator presses on the aforementioned one free end of asecond contact beam to elastically deform the aforementioned secondcontact beam, whereby the second contact point of the aforementionedother free end presses on the first surface of the flat flexible cable.2. An electrical connector recited in claim 1, wherein the secondcontact beam of the aforementioned second type of contact has a highrigidity from the one end being an actuator-driven portion, to theaforementioned joining portion, and has a low rigidity from theaforementioned joining portion to the other end.
 3. An electricalconnector recited in claim 1, wherein the aforementioned second contactbeam is slanted in the direction of the aforementioned fixed basedirection.
 4. An electrical connector recited in claim 1, wherein thelengths of each of the contact beams of the aforementioned two types ofcontacts are determined in such a way that there is a constant spacebetween each contact point in the flat flexible cable insertiondirection.